Passenger frustration with the value of an ever-more expensive rail network grew over the past year — even before January's inflation-busting fare rises took hold.

A survey of more than 30,000 rail users by the watchdog Passenger Focus found only 46% of passengers thought their ticket represented value for money.

The worst-performing train operator was National Express East Anglia, although most commuter routes in the south-east recorded below-average levels of satisfaction.

The survey found wide disparities in the ratings of different companies. While 84% were satisfied overall, on the beleaguered East Anglia service — a franchise since taken from National Express and now awarded to the Dutch operator Abellio — 77% of passengers were satisfied.

On some routes, barely one in two felt they had sufficient room to sit or stand.

Passengers' experience of punctuality and reliability ranged from 68% to 97% on different routes.

Anthony Smith, the chief executive of Passenger Focus, said: "The experience of Great Britain's passengers ranges from mediocre to good. This demonstrates that there is no such thing as the average passenger. Satisfaction with value for money has gone down, illustrating the impact that tough economic times, coupled with fare rises, are having.

"These results will enable the industry and government to focus resources and effort where passenger satisfaction remains in the doldrums. It can be done and passengers will give them credit when investment and pro-active management coincide."

London Overground and Merseyrail had recorded significant improvements, he said, adding that overall satisfaction with stations had gone up nationally.

Michael Roberts, chief executive of the Association of Train Operating Companies (ATOC), said: "Overall customer satisfaction remains at a record high level, though the survey results by route show that while there has been progress in many areas, there is no room for complacency.

"We recognise that value-for-money scores remain lower than others and the whole industry needs to focus on tackling costs as well as improving services."

• This article was amended on 26 January 2012. The headline incorrectly stated that more than 50% of rail users were dissatisfied with their service. The article itself and a picture caption wrongly asserted that one in four passengers on National Express East Anglia was dissatisfied.